By far the biggest flaw for many seems to be that it's called "Silent Hunter 4: Wolves of the Pacific" instead of "U-boats in the Atlantic something something something". I'm afraid there's no known workarounds for this, even with all the possible Atlantic mods.
Besides that there's some good old left-over from SH3 and some new ones: Don't stay near spawn areas for ships(usually but not always ports), don't save if you have damaged ships nearby, disable volumetric fog if you don't want "the ghost crew", come out of high TC while in the navmap view to prevent jelly water, avoid TC over 1024 so you don't mess the weather, etc...
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